The invention relates to an insulation member based on a non-woven material.
Insulation members of this kind are already known in a variety of forms. The known insulation members are however still not satisfactory in every respect in regard to different requirements which are to be developed in ever more combinations. Among these requirements there are numbered a high level of sound absorption and sound damping (indicated by the absorption coefficient as, and the sound damping value R); in addition also, high heat insulation (indicated by lambda), as well as low formation of liquid water in the event of large temperature gradients and high humidity gradients; these also combined to the greatest possible extent with comparatively low weight per unit area and ease of handling as a member to be installed.
The invention is therefore concerned with the technical problem of providing an insulation member based on a non-woven material which is distinguished by fulfilling one or more of the above-mentioned requirements to a high degree.
This technical problem is first and foremost solved wherein it is provided that the insulation member has a layered construction of different non-woven materials. In addition, this technical problem is also solved by the insulation member having a layered age construction of different foamed material. In the first-mentioned case, the different non-woven materials may also be combined with one or more foamed material layers and in the second-mentioned case, the different foamed materials may also be combined with one or more layers of non-woven material. The preferably different-degrees of density are advantageously achieved by different fibers and/or manufacturing methods for the non-woven material and/or foamed materials of different densities. A layer of non-woven material or a layer of foamed material, for example a non-woven material layer or a foamed material layer of a polyimide foamed material, is formed to be of very light weight for comparatively great volume. There are quite large intermediate spaces between the fibers. A further layer of non-woven material, here in the exemplary case, a melt-extruded non-woven spin material, is made more dense. By bringing together in layered manner different non-woven materials or non-woven material and foamed materials, the different properties are used in combination, in particular in regard to sound absorption. It is particularly preferred to provided the central layer as a layer of fleece non-woven material or as a layer of foamed material with very low volume weight, and to locate on each side of such a central layer, a non-woven material of a higher degree of densification, for example a layer as melt-extruded non-woven spin material. The central layer is also preferably formed with a greater thickness than the other layers, in particular the further layers of non-woven material; in the exemplary case, the further layers are the layers of melt extruded non-woven spin material. The layer of non-woven material of lesser density, here therefore preferable the central layer, has preferably also a thickness which in a multiple of the thickness of the layer of non-woven material of greater density, here therefore the two further non-woven material layers of melt-extruded non-woven spin material. The layers of non-woven material may also be covered over by layers of film. In particular, the layers of film are provided as outer layers. The layers of film may also be provided as intermediate layers. The outer films are further prefeably welded at the edge, but the layers of non-woven material or the layers of foamed material may be integrated in full or in part into the weld seam, substantially by compression to almost nil at the edge of the layers of non-woven material or of the layers of foamed material. Such compression at the edge may also be used to form a structural member. Fixing members may also be integrated into such a weld seam. The bringing together of the outer films is in this regard in a manner suitable for the entire connection to be held together solely by the films and optionally the layers of non-woven material or of foamed materials, connected at the edge or welded at the edge. An adhesive, a coating or the like for the individual layers is not required and is preferably also not provided. The layers are merely laid over one another in simple mannerxe2x80x94in each case outside the edge region. There in formed as it were a cushion having a cover provided by the outer films. Compressed regions resulting from welding, especially in the edge region, may in part contribute to accommodating fixing members and/or stiffening for the structural member. The multiple layers of non-woven material, optionally with integrated layers of foamed material, lead to a kind of pillow-type filling. It is of importance to the product that the formation of liquid water in the structural member is reduced. The films used, both the outer films and also optionally intermediate films, are also used which have directionally active permeabilities to water vapour. Preferably films are also used which have directionally active permeabilities to water vapour. Films may also be used which have moisture-dependent and/or temperature dependent permeabilities to water vapour.